I. Field of the Invention
The present invention relates to a telephone switching system connected to a plurality of telephone extensions for selectively connecting the extensions to each other and/or an external telephone line.
II. Description of the Prior Art
There are many previously known telephone switching systems, commonly called PBX systems, for selectively directing incoming telephone calls to a selected telephone extension in the telephone system. These previously known systems, however, all suffer from a number of common disadvantages. One disadvantage of these previously known systems is that such systems are expensive to obtain and maintain. While the expense of such systems is acceptable in many business settings, such telephone switching systems are economically infeasible for a home telephone system.
A still further disadvantage of these previously known telephone switching systems is that, upon a loss of power to the system, the entire system becomes inoperable and thus incapable of either receiving or sending telephone calls onto an external telephone line.